CN110943211A - Preparation method of high-performance Si/C negative electrode material - Google Patents
Preparation method of high-performance Si/C negative electrode material Download PDFInfo
- Publication number
- CN110943211A CN110943211A CN201911294209.2A CN201911294209A CN110943211A CN 110943211 A CN110943211 A CN 110943211A CN 201911294209 A CN201911294209 A CN 201911294209A CN 110943211 A CN110943211 A CN 110943211A
- Authority
- CN
- China
- Prior art keywords
- performance
- powder
- ball
- tank
- product
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/628—Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
- H01M4/386—Silicon or alloys based on silicon
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/624—Electric conductive fillers
- H01M4/625—Carbon or graphite
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
- H01M2004/027—Negative electrodes
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Abstract
The invention provides a preparation method of a high-performance Si/C cathode material, which relates to the technical field of composite material preparation, and mainly comprises the following steps: mixing clean rice hull with CO2Heat treatment in atmosphere, mixing the heat treated product with appropriate amount of NaCl and AlCl3Mixing Al or Mg powder, placing the mixture in a heat-insulating ball milling tank, and carrying out ball milling for 15-20 h at 160-200 ℃; soaking the ball-milled product with HCl acid and HF acid, centrifuging, washing, separating and vacuum drying to obtain the Si/C negative electrode material. The Si and C resources of the rice hulls are fully utilized, and the prepared Si/C negative electrode material is high in specific capacity, good in rate capability and excellent in cycle performance; meanwhile, the preparation method has the advantages of simple preparation process, high efficiency, no need of complex equipment, low cost and environmental friendlinessAnd can be directly used for industrial production.
Description
Technical Field
The invention relates to the technical field of composite material preparation, in particular to a preparation method of a high-performance Si/C cathode material.
Background
As a lithium ion battery cathode material, the specific capacity (theoretical capacity 3500mAh/g) of a Si material is far larger than that (theoretical capacity 372mAh/g) of a commercial graphite cathode material, and the Si is rich in storage capacity in the earth crust and low in price, so that the Si material is generally considered to be the lithium ion battery cathode material with the most application prospect. However, Si negative electrode materials expand heavily in volume during discharge, and Si expands up to 300% in volume in a fully lithium-intercalated state. Severe volume expansion causes Si particles to be broken, resulting in separation of Si particles from a conductive agent or a current collector, while a Solid Electrolyte Interface (SEI) film is continuously grown, thereby causing rapid decay of reversible capacity; in addition, the electronic conductivity of the pure Si material is very low, and it is difficult to satisfy the electron conductivity necessary for large current charge and discharge, resulting in severe attenuation of large current charge and discharge capacity.
Research shows that Si/C composite materials with various microstructures can be obtained by dispersing nano Si particles in a soluble organic compound, drying and carrying out heat treatment in inert atmosphere; compared with a pure Si material, the electrochemical performance of the Si/C cathode material is obviously improved. However, the preparation difficulty of the high-dispersity nano Si is high, the micro-morphology of the high-dispersity nano Si is difficult to control after the high-dispersity nano Si is compounded with the C material, and how to realize the uniform coating of the high-dispersity nano Si particles by the C material is still a main technical problem in the preparation of the Si/C cathode material; in addition, the preparation process of the Si/C cathode material is complex, the efficiency is low, and the cost is high. These factors limit the commercial application of Si/C anode materials. In recent years, research on the preparation of high-performance Si/C negative electrode materials by adopting a new Si source and a low-cost and environment-friendly way becomes a research hotspot in the field.
The rice is one of the main food crops in China, the annual output is nearly 2 hundred million tons, and about 4000 million tons of rice husks are produced annually.Researches show that the main components of the rice hulls comprise crude fiber, lignin, pentosan, ash and the like, wherein the ash accounts for 13-22 wt%, and SiO in the ash2Accounts for 97.3 wt%; wherein the Si component is uniformly embedded in organic matrixes such as cellulose, lignin and the like. Therefore, the rice hull is a renewable high-quality Si and C resource and is an ideal precursor for preparing the Si/C composite material. So far, the method for preparing the lithium ion battery cathode material by using the rice hull resource is only limited to extracting the Si component in the rice hull, compounding the Si component with an organic compound, and carrying out heat treatment in an inert atmosphere to prepare the Si/C cathode material. The subject group of researchers in Guo Yu nationality of Chinese academy of sciences fully burns rice hulls in air atmosphere to obtain pure SiO2The obtained SiO is subjected to a high-temperature (680 ℃) magnesiothermic reduction method2Reducing, and removing MgO and MgSi in the magnesium thermal reduction product by HCl acid2Dispersing the obtained pure Si powder and organic compounds such as polyaniline in a dimethylformamide solvent to prepare stable slurry, and carrying out electrostatic spraying and subsequent high-temperature heat treatment to prepare the Si/C cathode material. Obviously, the existing method for preparing the Si/C cathode material by using the rice hulls as the raw materials not only wastes high-quality C resources in the rice hulls and discharges a large amount of greenhouse gases, but also has the disadvantages of complex preparation method, low efficiency and higher cost.
Disclosure of Invention
Technical problem to be solved
Aiming at the defects of the prior art, the invention provides the preparation method of the high-performance Si/C cathode material, which has the advantages of simple process, high efficiency, low cost, environmental friendliness and suitability for mass preparation.
(II) technical scheme
In order to achieve the purpose, the invention is realized by the following technical scheme:
a preparation method of a high-performance Si/C negative electrode material comprises the following steps:
1) removing impurities from rice hulls, cleaning and drying the rice hulls, putting the obtained clean rice hulls into a horizontal tubular furnace, heating the rice hulls to 850-950 ℃ at the speed of 5-10 ℃/min in the atmosphere of N2, and switching N2 into CO2In CO2Subjecting the hulls to a constant temperature heat treatment in an atmosphere followed by a N2 atmosphereNaturally cooling to below 100 ℃ in atmosphere to obtain a rice hull heat treatment product;
2) putting the rice hull heat treatment product into a wear-resistant steel tank, and adding NaCl and AlCl3The method comprises the following steps of (1) screwing and sealing a tank cover, opening an air inlet valve and an air outlet valve on the tank cover, introducing Ar gas into a ball milling tank, flushing the ball milling tank by the Ar gas to remove air and water vapor in the ball milling tank, and then closing the air outlet valve and the air inlet valve in sequence;
3) tightly wrapping a sealed wear-resistant steel tank with heat-insulating cotton, inserting a thermometer between the outer wall of the ball-milling tank and the heat-insulating cotton to monitor the temperature of the tank body, fixing the wear-resistant steel tank on a planetary ball mill, setting ball-milling working conditions, and performing ball-milling treatment on a reaction system in the wear-resistant steel tank;
4) and taking out the ball-milled product, placing the ball-milled product in HCl acid, continuously stirring for 3-5 h, then carrying out centrifugal separation, washing the obtained solid product with dilute HF acid for 3-5 min, then carrying out deionized water washing and centrifugal separation processes, repeating the processes for 3 times, and carrying out vacuum drying treatment on the separated product at 70-80 ℃ to obtain the black Si/C cathode material.
Further, in the step 1), the flow rate of N2 is 100-200 mL/min, and CO is2The flow rate is 200-600 mL/min, and the time of constant temperature heat treatment is 1-3 h.
Further, in the step 2), NaCl and AlCl are added3The mol percentage of NaCl in the mixed salt is 37.3-43.2%, and AlCl is3The mol percentage of the aluminum powder to the rice hull is 56.8-62.7%, the Al powder or Mg powder is an analytical pure grade, the particle size is 100-300 meshes, and the mass ratio of the Al powder to the rice hull heat treatment product is 1: 3.5-4.0, or the mass ratio of the Mg powder to the rice hull heat treatment product is 1: 1.2 to 1.8.
Further, in the step 2), the total mass of the rice hull heat treatment product and the Al powder is equal to that of NaCl and AlCl3The total mass ratio of the mixed salt is 1: 2.8-3.5, or the total mass of the rice hull heat treatment product and the Mg powder and NaCl and AlCl3The total mass ratio of the mixed salt is 1: 2.5 to 3.0.
Further, in the step 2), NaCl and AlCl are added3Mixed salt, rice hull heat-treated product, Al powder or MThe mass ratio of the reaction system consisting of the g powder to the wear-resistant steel balls is 1: 10-15.
Further, in the step 3), the temperature of the wear-resistant steel tank body is 160-200 ℃, and the working conditions of the ball mill are as follows: and in an intermittent working mode, the rotating speed is 400-450 rpm, and the total ball milling time is 15-20 h.
Further, in the step 4), the concentration of HCl acid is 8-15 wt%, and the concentration of dilute HF acid is 5-10 wt%.
Further, the Si source and the C source required for preparing the Si/C cathode material are completely derived from rice hull raw materials, and other forms of Si sources and C sources are not involved.
(III) advantageous effects
The invention provides a preparation method of a high-performance Si/C negative electrode material, which has the following beneficial effects:
1. si and C resources in the rice hulls are fully utilized to prepare a Si/C composite material with a more ideal microstructure, wherein nano Si particles are uniformly embedded in an amorphous C matrix, and the C matrix simultaneously serves as a conductive agent, a coating layer of nano Si and an elastic layer for stress release; as a lithium ion battery cathode material, the Si/C material has more excellent electrochemical performance.
2. Designs cheap and efficient NaCl-AlCl3The binary low-melting-point (109-157 ℃) fused salt can be lower than AlCl3The temperature of the boiling point (183 ℃) is molten, so that AlCl can be effectively avoided3Volatilize to form AlCl3The amount of the fused salt is increased, and AlCl can be avoided3And the volatile component can aggravate the corrosion of working equipment and the pollution of production environment.
3. Physical activation and NaCl-AlCl by means of mechanical ball milling3The chemical activation of the molten salt improves the reduction capability of the low-temperature aluminothermic or magnesiothermic reaction and can efficiently reduce SiO in the C matrix2So that the generated nano Si has no large grain diameter and is uniformly distributed in the C matrix.
4. Using only rice husk, NaCl and AlCl3And Mg or Al powder and the like are cheap raw materials, so the preparation cost is low; mg or Al powder (100-300 meshes) with relatively large particle size is allowed to be used as a reducing agent, so that the preparation process is simplified, the cost of raw materials is reduced, and the Mg powder is avoidedOr safety risks during transportation, storage and production of Al powder raw materials.
5. The preparation method disclosed by the invention is simple in process, free of complex equipment, low in cost, environment-friendly and capable of being directly used for industrial production.
Drawings
FIG. 1: the X-ray diffraction (XRD) pattern of the Si/C negative electrode material prepared in example 1 of the present invention.
FIG. 2: a Field Emission Scanning Electron Microscope (FESEM) picture of the Si/C negative electrode material prepared in example 1 of the present invention.
FIG. 3: the Si/C cathode material prepared in the embodiment 1 of the invention has constant current charge and discharge curves at different current densities.
FIG. 4: the cycle performance and coulombic efficiency chart of the Si/C cathode material prepared in the embodiment 1 of the invention (the current density of the first 4 circles is 0.1A/g, and the current density of the subsequent 196 circles is 1A/g);
FIG. 5: the X-ray diffraction (XRD) pattern of the Si/C negative electrode material prepared in example 2 of the present invention.
FIG. 6: a Field Emission Scanning Electron Microscope (FESEM) picture of the Si/C negative electrode material prepared in example 2 of the present invention.
FIG. 7: the Si/C cathode material prepared in the embodiment 2 of the invention has constant current charge and discharge curves at different current densities.
FIG. 8: the cycling performance and coulombic efficiency of the Si/C anode material prepared in example 2 of the present invention (current density 0.1A/g for the first 4 cycles, and 1A/g for the subsequent 196 cycles).
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1:
a preparation method of a high-performance Si/C negative electrode material comprises the following steps:
(1) removing impurities from rice hulls obtained from a rice factory, cleaning and drying to obtain a clean rice hull raw material;
(2) weighing 100g of clean rice hulls, placing the rice hulls in a constant temperature area in a horizontal tubular furnace in N2In the atmosphere (N)2Flow rate of 100mL/min) was increased to 850 ℃ at 5 ℃/min, N was added2Atmosphere switching to CO2Atmosphere (CO)2Flow rate of 200mL/min), heat treatment at constant temperature for 2h, and then N2Naturally cooling to below 100 ℃ in the atmosphere;
(3) weighing NaCl2.86g and AlCl310.94g, grinding and uniformly mixing the two in a dry environment, then weighing 3.6g of the rice hull heat treatment product and 1.0g of aluminum powder (100-200 meshes), adding the rice hull heat treatment product and the aluminum powder into a wear-resistant steel tank, adding 230g of wear-resistant steel balls, sealing a ball mill tank cover, opening an upper air inlet valve and an air outlet valve of the tank cover, flushing the raw materials in the tank by Ar gas, removing oxygen and water vapor, and then closing the air outlet valve and the air inlet valve;
(4) tightly wrapping a sealed wear-resistant steel tank by using heat insulation cotton, inserting a thermometer between the outer wall of the steel tank and the heat insulation cotton, fixing the steel tank on a planetary ball mill, and carrying out ball milling on a reaction system in the steel tank, wherein the ball mill is set to be in an intermittent working mode, the rotating speed is 400rpm, and the total ball milling time is 15 h; controlling the temperature of the tank body to be 160-200 ℃, the temperature of the tank body to be higher than 200 ℃, suspending the operation of the ball mill to be lower than 160 ℃, and resuming the operation of the ball mill;
(5) and placing the ball-milled product in 10 wt% HCl acid, continuously stirring for 3h, then performing centrifugal separation, washing the obtained solid product with dilute 5 wt% HF acid for 5min, washing with deionized water, performing centrifugal separation, repeating the process for 3 times, and performing vacuum drying treatment on the separated product at 70 ℃ to obtain a black powder material.
The X-ray diffraction (XRD) pattern of the powder material is shown in figure 1, and the black powder material prepared by the embodiment is composed of cubic system Si (JCPDSno.27-1402) with higher crystallinity and amorphous C; the photograph of a Field Emission Scanning Electron Microscope (FESEM) is shown in FIG. 2, and the black powder material obtained in this example is composed of submicron-sized random agglomerates in which the primary particles have a particle size of less than 50 nm. As shown in FIG. 3, the current density of the Si/C negative electrode material prepared in this example is 0.10A/g, the first discharge capacity and the first charge capacity are 1850 and 1245mAh/g, respectively, the first coulombic efficiency is 67.0%, and when the current density is increased to 4A/g, the specific capacity is 957 mAh/g. The cycle performance and the coulombic efficiency chart are shown in fig. 4, the coulombic efficiency of the Si/C negative electrode material prepared in the embodiment is rapidly increased from 65.4% to more than 97.3% after 4 cycles of 0.1A/g cycle, and then reaches as high as 99.7% after 196 cycles of 1A/g cycle; after 200 cycles, the capacity of the cathode material is still 1055mAh/g, and the capacity retention rate is 91.3%. As can be seen, the Si/C anode material prepared by the embodiment shows excellent electrochemical performance.
The electrochemical performance of the Si/C negative electrode material is evaluated by using a simulated battery sample, and the manufacturing method of the simulated battery sample comprises the following steps: uniformly mixing Si/C active substance, conductive carbon black and sodium alginate (the mass ratio is 80:15:5) to prepare a working electrode, assembling the working electrode into a CR2025 button cell by taking a lithium foil as a reference electrode and a counter electrode and taking Celgard2400 polypropylene porous membrane as a diaphragm, wherein the electrolyte is 1mol/LLIPF6EC + DEC (EC and DEC in a 1:1 volume ratio).
Example 2:
a preparation method of a high-performance Si/C negative electrode material comprises the following steps:
(1) removing impurities from the obtained rice hulls, cleaning and drying;
(2) weighing 100g of clean rice hulls, placing the rice hulls in a constant temperature area in a horizontal tubular furnace in N2In the atmosphere (N)2Flow rate of 150mL/min) was increased to 950 ℃ at 10 ℃/min, N was added2Atmosphere switching to CO2Atmosphere (CO)2Flow rate of 600mL/min), heat treatment at constant temperature for 3h, then in N2Naturally cooling to below 100 ℃ in the atmosphere;
(3) weighing NaCl4.51g and AlCl315.09g, grinding and mixing the two in a dry environment uniformly, weighing 4.20g of the rice hull heat treatment product and 2.33g of magnesium powder (100-200 meshes), adding the two into a wear-resistant steel tank, adding 340g of wear-resistant steel balls, sealing the cover of the ball mill tank, opening the cover, and uniformly mixing the twoAn upper air inlet valve and an air outlet valve of the tank cover are used for flushing the raw materials in the tank by Ar gas to remove oxygen and water vapor, and then the air outlet valve and the air inlet valve are closed;
(4) tightly wrapping a sealed wear-resistant steel tank by using heat insulation cotton, inserting a thermometer between the outer wall of the steel tank and the heat insulation cotton, fixing the steel tank on a planetary ball mill, and carrying out ball milling on a reaction system in the steel tank, wherein the ball mill is set to be in an intermittent working mode, the rotating speed is 450rpm, and the total ball milling time is 18 h; controlling the temperature of the tank body to be 160-200 ℃, the temperature of the tank body to be higher than 200 ℃, suspending the operation of the ball mill to be lower than 160 ℃, and resuming the operation of the ball mill;
(5) placing the ball-milling reaction product in 15 wt% HCl acid, continuously stirring for 5h, then performing centrifugal separation, washing the obtained solid product with diluted 10 wt% HF acid for 3min, then washing with deionized water, performing centrifugal separation, repeating the process for 3 times, and performing vacuum drying treatment on the separated product at 75 ℃ to obtain a black powder material.
The XRD pattern (FIG. 5) of the powder material shows that the black powder material prepared in this example is composed of cubic system Si (JCPDSno.27-1402) with higher crystallinity and amorphous C; the FESEM photograph (fig. 6) shows that the black powder material produced in this example consists of submicron-sized random agglomerates with primary particle size of less than 50 nm. The constant-current charge-discharge curve (fig. 7) shows that the current density of the Si/C negative electrode material prepared in the embodiment is 0.10A/g, the first discharge capacity and the first charge capacity are 2040 mAh/g and 1392mAh/g respectively, the first coulombic efficiency is 68.2%, and when the current density is increased to 4A/g, the specific capacity is 1153 mAh/g. The cycle performance and coulombic efficiency chart (fig. 8) shows that the coulombic efficiency of the Si/C anode material prepared in the embodiment rapidly increases from 68.4% to more than 92.6% after 4 cycles of 0.1A/g cycle, and then reaches as high as 99.7% after 196 cycles of 1A/g cycle; after 200 cycles, the capacity of the Si/C negative electrode material is still as high as 1288mAh/g, and the capacity is not obviously attenuated. As can be seen, the Si/C anode material prepared by the embodiment shows excellent electrochemical performance. The test simulated cell samples were made in the same manner as in example 1.
Example 3:
a preparation method of a high-performance Si/C negative electrode material comprises the following steps:
(1) removing impurities from the rice hull raw material, cleaning and drying;
(2) weighing 100g of clean rice hulls, placing the rice hulls in a constant temperature area in a horizontal tubular furnace in N2In the atmosphere (N)2Flow rate of 150mL/min) was increased to 900 ℃ at 10 ℃/min, N was added2Atmosphere switching to CO2Atmosphere (CO)2Flow 400mL/min), heat treatment at constant temperature for 2h, then in N2Naturally cooling to below 100 ℃ in the atmosphere;
(3) weighing NaCl4.93g and AlCl315.20g, grinding and uniformly mixing the two in a dry environment, weighing 4.5g of the rice hull heat treatment product and 1.25g of aluminum powder (100-200 meshes), adding the two into a wear-resistant steel tank, adding 365g of wear-resistant steel balls, sealing a ball mill tank cover, opening an upper air inlet valve and an air outlet valve of the tank cover, flushing the raw materials in the tank by Ar gas, removing oxygen and water vapor, and then closing the air outlet valve and the air inlet valve;
(4) tightly wrapping a sealed wear-resistant steel tank by using heat insulation cotton, inserting a thermometer between the outer wall of the steel tank and the heat insulation cotton, fixing the steel tank on a planetary ball mill, and carrying out ball milling on a reaction system in the steel tank, wherein the ball mill is set to be in an intermittent working mode, the rotating speed is 450rpm, and the total ball milling time is 20 hours; controlling the temperature of the tank body to be 160-200 ℃, the temperature of the tank body to be higher than 200 ℃, suspending the operation of the ball mill to be lower than 160 ℃, and resuming the operation of the ball mill;
(5) placing the ball-milling reaction product in 15 wt% HCl acid, continuously stirring for 4h, then performing centrifugal separation, washing the obtained solid product with diluted 8 wt% HF acid for 4min, washing with deionized water, performing centrifugal separation, repeating the process for 3 times, and performing vacuum drying treatment on the separated product at 80 ℃ to obtain a black powder material.
XRD analysis shows that the black powder material prepared by the embodiment consists of cubic system Si with higher crystallinity and amorphous C; FESEM analysis showed that the black powder material consisted of submicron random agglomerates with primary particle size of less than 50 nm. Analysis of a constant-current charge-discharge curve shows that the Si/C negative electrode material prepared in the embodiment has the current density of 0.10A/g, the first discharge capacity and the first charge capacity of 1985 mAh/g and 1302mAh/g respectively, the first coulombic efficiency of 65.6 percent, and when the current density is increased to 4A/g, the specific capacity is 1023 mAh/g. The coulombic efficiency of the Si/C negative electrode material prepared in the embodiment is rapidly increased from 65.3% to more than 96.8% after 4 cycles of 0.1A/g circulation, and then reaches 99.8% after 196 cycles of 1A/g circulation; after 200 cycles, the capacity of the cathode material is still as high as 1165mAh/g, and the capacity retention rate is 93.1%. As can be seen, the Si/C anode material prepared by the embodiment shows excellent electrochemical performance.
The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (8)
1. The preparation method of the high-performance Si/C negative electrode material is characterized by comprising the following steps of:
1) removing impurities from rice hulls, cleaning, drying, placing the obtained clean rice hulls in a horizontal tube furnace, and performing nitrogen oxidation treatment on the clean rice hulls2Heating to 850-950 ℃ at a speed of 5-10 ℃/min in the atmosphere, and then adding N2Switching to CO2In CO2Subjecting the hulls to a constant temperature heat treatment in an atmosphere followed by N2Naturally cooling to below 100 ℃ in the atmosphere to obtain a rice hull heat treatment product;
2) putting the rice hull heat treatment product into a wear-resistant steel tank, and adding NaCl and AlCl3The method comprises the following steps of (1) screwing and sealing a tank cover, opening an air inlet valve and an air outlet valve on the tank cover, introducing Ar gas into a ball milling tank, flushing the ball milling tank by the Ar gas to remove air and water vapor in the ball milling tank, and then closing the air outlet valve and the air inlet valve in sequence;
3) tightly wrapping a sealed wear-resistant steel tank with heat-insulating cotton, inserting a thermometer between the outer wall of the ball-milling tank and the heat-insulating cotton to monitor the temperature of the tank body, fixing the wear-resistant steel tank on a planetary ball mill, setting ball-milling working conditions, and performing ball-milling treatment on a reaction system in the wear-resistant steel tank;
4) and taking out the ball-milled product, placing the ball-milled product in HCl acid, continuously stirring for 3-5 h, then carrying out centrifugal separation, washing the obtained solid product with dilute HF acid for 3-5 min, then carrying out deionized water washing and centrifugal separation processes, repeating the processes for 3 times, and carrying out vacuum drying treatment on the separated product at 70-80 ℃ to obtain the black Si/C cathode material.
2. The method for preparing the high-performance Si/C anode material according to claim 1, wherein in the step 1), N is2Flow rate of 100-200 mL/min, CO2The flow rate is 200-600 mL/min, and the time of constant temperature heat treatment is 1-3 h.
3. The method for preparing the high-performance Si/C anode material according to claim 1, wherein in the step 2), NaCl and AlCl are added3The mol percentage of NaCl in the mixed salt is 37.3-43.2%, and AlCl is3The Al powder or Mg powder is of analytical pure grade, the particle size is 100-300 meshes, and the mass ratio of the Al powder to the rice hull heat treatment product is 1: 3.5-4.0, or the mass ratio of the Mg powder to the rice hull heat treatment product is 1: 1.2 to 1.8.
4. The method for preparing a high-performance Si/C anode material according to claim 1, wherein in the step 2), the total mass of the thermal-treated product of rice hulls and Al powder and NaCl and AlCl are used3The total mass ratio of the mixed salt is 1: 2.8-3.5, or the total mass of the rice hull heat treatment product and the Mg powder and NaCl and AlCl3The total mass ratio of the mixed salt is 1: 2.5 to 3.0.
5. The method for preparing the high-performance Si/C anode material according to claim 1, wherein NaCl and AlCl are used in the step 2)3The mass of the reaction system consisting of the mixed salt, the thermal treatment product of the rice hull, the Al powder or the Mg powder and the wear-resistant steel ballThe ratio is 1: 10-15.
6. The preparation method of the high-performance Si/C anode material as claimed in claim 1, wherein in the step 3), the temperature of the wear-resistant steel can body is 160-200 ℃, and the working conditions of the ball mill are as follows: and in an intermittent working mode, the rotating speed is 400-450 rpm, and the total ball milling time is 15-20 h.
7. The method for preparing the high-performance Si/C anode material according to claim 1, wherein in the step 4), the concentration of HCl acid is 8-15 wt%, and the concentration of dilute HF acid is 5-10 wt%.
8. The preparation method of the high-performance Si/C negative electrode material as claimed in claim 1, wherein the Si source and the C source required for preparing the Si/C negative electrode material are completely derived from rice hull raw materials, and do not relate to other forms of Si sources and C sources.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911294209.2A CN110943211A (en) | 2019-12-16 | 2019-12-16 | Preparation method of high-performance Si/C negative electrode material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911294209.2A CN110943211A (en) | 2019-12-16 | 2019-12-16 | Preparation method of high-performance Si/C negative electrode material |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110943211A true CN110943211A (en) | 2020-03-31 |
Family
ID=69911400
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911294209.2A Pending CN110943211A (en) | 2019-12-16 | 2019-12-16 | Preparation method of high-performance Si/C negative electrode material |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110943211A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111900348A (en) * | 2020-07-14 | 2020-11-06 | 中国科学院山西煤炭化学研究所 | Method for preparing silicon-carbon composite material based on ball milling method and application thereof |
| CN114735704A (en) * | 2022-05-25 | 2022-07-12 | 安徽工业大学 | Method for synthesizing nano silicon carbide at low temperature |
| WO2022225469A1 (en) * | 2021-04-19 | 2022-10-27 | Khon Kaen University | High-purity nanosilica and nanosilicon manufacturing process |
| CN116014107A (en) * | 2023-02-09 | 2023-04-25 | 湖南钠能时代科技发展有限公司 | Silicon-carbon anode material based on silicon-rich biomass raw material and preparation method thereof |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103579596A (en) * | 2013-11-08 | 2014-02-12 | 合肥国轩高科动力能源股份公司 | Preparation method of lithium ion battery cathode material |
| CN104009210A (en) * | 2014-05-04 | 2014-08-27 | 昆明理工大学 | Porous silicon/carbon composite material, and preparation method and application thereof |
| KR20140144590A (en) * | 2013-06-11 | 2014-12-19 | 한국과학기술원 | Active materia for anode of lithium secondary battery originated from rice husk and manufacturing method for the same |
| CN104617275A (en) * | 2015-02-11 | 2015-05-13 | 武汉科技大学 | Method for preparing silicon-carbon compound from silicon-containing biomass as raw material as well as prepared silicon-carbon compound and application thereof |
| CN105932240A (en) * | 2016-05-11 | 2016-09-07 | 武汉科技大学 | Nano-silicon-carbon compound and preparation method and application thereof |
| CN108199023A (en) * | 2017-12-30 | 2018-06-22 | 吉林大学 | The preparation method of biological silicon carbon material, biological silicon carbon material and application |
| CN109694075A (en) * | 2018-12-18 | 2019-04-30 | 安徽工业大学 | A kind of low temperature ball milling nano silica fume, preparation method and application |
| CN109721057A (en) * | 2018-12-29 | 2019-05-07 | 安徽工业大学 | A kind of high efficient cryogenic molten salt preparation method of nano-silicon |
-
2019
- 2019-12-16 CN CN201911294209.2A patent/CN110943211A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20140144590A (en) * | 2013-06-11 | 2014-12-19 | 한국과학기술원 | Active materia for anode of lithium secondary battery originated from rice husk and manufacturing method for the same |
| CN103579596A (en) * | 2013-11-08 | 2014-02-12 | 合肥国轩高科动力能源股份公司 | Preparation method of lithium ion battery cathode material |
| CN104009210A (en) * | 2014-05-04 | 2014-08-27 | 昆明理工大学 | Porous silicon/carbon composite material, and preparation method and application thereof |
| CN104617275A (en) * | 2015-02-11 | 2015-05-13 | 武汉科技大学 | Method for preparing silicon-carbon compound from silicon-containing biomass as raw material as well as prepared silicon-carbon compound and application thereof |
| CN105932240A (en) * | 2016-05-11 | 2016-09-07 | 武汉科技大学 | Nano-silicon-carbon compound and preparation method and application thereof |
| CN108199023A (en) * | 2017-12-30 | 2018-06-22 | 吉林大学 | The preparation method of biological silicon carbon material, biological silicon carbon material and application |
| CN109694075A (en) * | 2018-12-18 | 2019-04-30 | 安徽工业大学 | A kind of low temperature ball milling nano silica fume, preparation method and application |
| CN109721057A (en) * | 2018-12-29 | 2019-05-07 | 安徽工业大学 | A kind of high efficient cryogenic molten salt preparation method of nano-silicon |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111900348A (en) * | 2020-07-14 | 2020-11-06 | 中国科学院山西煤炭化学研究所 | Method for preparing silicon-carbon composite material based on ball milling method and application thereof |
| CN111900348B (en) * | 2020-07-14 | 2021-10-22 | 中国科学院山西煤炭化学研究所 | Method for preparing silicon-carbon composite material based on ball milling method and application thereof |
| WO2022225469A1 (en) * | 2021-04-19 | 2022-10-27 | Khon Kaen University | High-purity nanosilica and nanosilicon manufacturing process |
| CN114735704A (en) * | 2022-05-25 | 2022-07-12 | 安徽工业大学 | Method for synthesizing nano silicon carbide at low temperature |
| CN114735704B (en) * | 2022-05-25 | 2024-01-05 | 安徽工业大学 | Method for synthesizing nano silicon carbide at low temperature |
| CN116014107A (en) * | 2023-02-09 | 2023-04-25 | 湖南钠能时代科技发展有限公司 | Silicon-carbon anode material based on silicon-rich biomass raw material and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110943211A (en) | Preparation method of high-performance Si/C negative electrode material | |
| CN110828808B (en) | Preparation method and application of lithium-sulfur battery positive electrode material | |
| CN106299365A (en) | A kind of sodium-ion battery biomass hard carbon cathode material, preparation method and sodium-ion battery | |
| CN105762360A (en) | Graphene-silicon-coated composite negative electrode material and preparing method and application thereof | |
| CN103367719A (en) | Yolk-shell structure tin dioxide-nitrogen-doped carbon material and preparation method thereof | |
| CN106654221A (en) | Three-dimensional porous carbon-coated zinc selenide material for lithium ion battery anodes and preparation method of material | |
| CN110600695B (en) | Yolk-eggshell structure tin@hollow mesoporous carbon sphere material and preparation method thereof | |
| CN109755540B (en) | Lithium-sulfur battery positive electrode material and preparation method thereof | |
| CN103730638A (en) | Preparation method of nitrogen-doped carbon material | |
| CN114122397B (en) | Carbon nanotube-connected double-carbon-layer-coated mesoporous silica composite material and preparation method and application thereof | |
| CN102916178A (en) | Preparation method of carbon cladding modified lithium manganate anode material | |
| CN115092905B (en) | Amorphous carbon material modified by carbon dots, and preparation method and application thereof | |
| CN113270587A (en) | Preparation method and application of high-stability silicon-based composite material constructed by in-situ fluorination | |
| CN116803899A (en) | Biomass-derived hard carbon material, preparation method thereof, sodium ion battery negative electrode plate and sodium ion battery | |
| CN111960422A (en) | Preparation method and application of two-dimensional silicon nanomaterial | |
| CN109755542B (en) | Sodium-sulfur battery positive electrode material and preparation method thereof | |
| CN110518227B (en) | Lithium-sulfur battery positive electrode material and preparation method thereof | |
| CN109860571B (en) | Lithium-sulfur battery positive electrode material and preparation method and application thereof | |
| CN115403028B (en) | Preparation method of anode material, anode material and sodium ion battery | |
| CN108417806B (en) | Preparation method of sulfur/carbon composite positive electrode material of lithium-sulfur battery | |
| CN113428865B (en) | Pomegranate-like silicon-based negative electrode material and preparation method thereof | |
| CN113942991B (en) | Silicon carbon-graphite composite negative electrode material and preparation method thereof | |
| CN113130873B (en) | Porous bismuth-carbon material, preparation method and application thereof | |
| CN113745491B (en) | SnO with double-wall hollow ball structure 2 @ C material and preparation method thereof | |
| CN111740095B (en) | Carbon microsphere coated zinc oxide nanosheet material and preparation method and application thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20200331 |